Highly Efficient Catalytic Microengines: Template Electrosynthesis of Polyaniline/Platinum Microtubes

Highly efficient catalytic microtubular engines are synthesized rapidly and inexpensively using an electrochemical growth of bilayer polyaniline/platinum microtubes within the conically shaped pores of a polycarbonate template membrane. These mass-produced microtubular engines are only 8 μm long, are self-propelled at an ultrafast speed (of over 350 body lengths s^(–1)), and can operate in very low levels of the hydrogen peroxide fuel (down to 0.2%). The propulsion characteristics and optimization of these microtubular engines are described, along with their efficient operation in different biological environments which holds great promise for biomedical applications

Efficient bubble propulsion of polymer-based microengines in real-life environments

Template-electrodeposited polymer/Pt microtube engines display efficient propulsion in a wide range of real-life samples ranging from seawater to human serum. Remarkably high speeds are observed in fuel-enhanced raw serum, apple juice, seawater, lake and river water samples. Our results indicate that polymer-based microengines hold considerable promise for diverse practical applications and that real samples exert different effects upon propulsion of different bubble-propelled microtube engines

Highly Efficient Catalytic Microengines: Template Electrosynthesis of Polyaniline/Platinum Microtubes

Highly efficient catalytic microtubular engines are synthesized rapidly and inexpensively using an electrochemical growth of bilayer polyaniline/platinum microtubes within the conically shaped pores of a polycarbonate template membrane. These mass-produced microtubular engines are only 8 μm long, are self-propelled at an ultrafast speed (of over 350 body lengths s^(–1)), and can operate in very low levels of the hydrogen peroxide fuel (down to 0.2%). The propulsion characteristics and optimization of these microtubular engines are described, along with their efficient operation in different biological environments which holds great promise for biomedical applications

Diseño, construcción e implementación de un dispositivo de telecomunicaciones mediante fibra óptica, con guía de laboratorio para la realización de prácticas /

El presente trabajo consiste en el diseño y elaboración de un dispositivo capaz de realizar enlaces punto a punto por medio de fibra óptica, en la figura se muestra el proceso necesario para llevar a cabo esta función. El dispositivo a implementar consta de una etapa de modulación, siendo capaz de realizarse la operación con modulación PWM o con modulación 4QAM. Luego tenemos la etapa de transmisión que se realiza por medio de un transductor de señales de voltaje y corriente a señales ópticas (fotodiodo LED), a partir de aquí se transmite la señal a través de la fibra y en el otro extremo aparece la etapa de recepción realizada a través de un transductor que se encarga de transformar las señales ópticas (fotodiodo PIN) a señales de voltaje y corriente, para luego recuperar los datos originales a través de la etapa de demodulación y acondicionamiento.Incluye bibliografía, anexo

Graphene-based Janus micromotors for the dynamic removal of pollutants

Persistent organic pollutants (POPs) are ubiquitous in the environment as a result of modern industrial processes. We present an effective POPs decontamination strategy based on their dynamic adsorption at the surface of reduced graphene oxide (rGO)-coated silica (SiO)-Pt Janus magnetic micromotors for their appropriate final disposition. While the motors rapidly move in a contaminated solution, the adsorption of POPs efficiently takes place in a very short time. Characterization of the micromotors both from the materials and from the motion point of view was performed. Polybrominated diphenyl ethers (PBDEs) and 5-chloro-2-(2,4-dichlorophenoxy) phenol (triclosan) were chosen as model POPs and the removal of the contaminants was efficiently achieved. The rGO-coated micromotors demonstrated superior adsorbent properties with respect to their concomitant GO-coated micromotors, static rGO-coated particles and dynamic silica micromotors counterparts. The extent of decontamination was studied over the number of micromotors, whose magnetic properties were used for their collection from environmental samples. The adsorption properties were maintained for 4 cycles of micromotors reuse. The new rGO-coated SiO functional material-based micromotors showed outstanding capabilities towards the removal of POPs and their further disposition, opening up new possibilities for efficient environmental remediation of these hazardous compounds

Multi-Fuel Driven Janus Micromotors

Here the first example of a chemically powered micromotor that harvests its energy from the reactions of three different fuels is presented. The new Al/Pd Janus microspheres—prepared by depositing a Pd layer on one side of Al microparticles—are propelled efficiently by the thrust of hydrogen bubbles generated from different reactions of Al in strong acidic and alkaline environments, and by an oxygen bubble thrust produced at their partial Pd coating in hydrogen peroxide media. High speeds and long lifetimes of 200 μm s^(−1) and 8 min are achieved in strong alkaline media and acidic media, respectively. The ability to autonomously adapt to the presence of a new fuel (surrounding environment), without compromising the propulsion behavior is illustrated. These data also represent the first example of a chemically powered micromotor that propels autonomously and efficiently in alkaline environments (pH > 11) without additional fuels. The ability to use multiple fuel sources to power the same micromotor offers a broader scope of operation and considerable promise for diverse applications of micromotors in different chemical environments

Multi-Fuel Driven Janus Micromotors

Here the first example of a chemically powered micromotor that harvests its energy from the reactions of three different fuels is presented. The new Al/Pd Janus microspheres—prepared by depositing a Pd layer on one side of Al microparticles—are propelled efficiently by the thrust of hydrogen bubbles generated from different reactions of Al in strong acidic and alkaline environments, and by an oxygen bubble thrust produced at their partial Pd coating in hydrogen peroxide media. High speeds and long lifetimes of 200 μm s^(−1) and 8 min are achieved in strong alkaline media and acidic media, respectively. The ability to autonomously adapt to the presence of a new fuel (surrounding environment), without compromising the propulsion behavior is illustrated. These data also represent the first example of a chemically powered micromotor that propels autonomously and efficiently in alkaline environments (pH > 11) without additional fuels. The ability to use multiple fuel sources to power the same micromotor offers a broader scope of operation and considerable promise for diverse applications of micromotors in different chemical environments

Dynamic Isolation and Unloading of Target Proteins by Aptamer-Modified Microtransporters

We describe here a new strategy for isolating target proteins from complex biological samples based on an aptamer-modified self-propelled microtube engine. For this purpose, a thiolated thrombin or a mixed thrombin–ATP aptamer (prehybridized with a thiolated short DNA) was coassembled with mercaptohexanol onto the gold surface of these microtube engines. The rapid movement of the aptamer-modified microtransporter resulted in highly selective and rapid capture of the target thrombin, with an effective discrimination against a large excess of nontarget proteins. Release of the captured thrombin can be triggered by the addition of ATP that can bind and displace the immobilized mixed thrombin–ATP aptamer in 20 min. The rapid loading and unloading abilities demonstrated by these selective microtransporters are illustrated in complex matrixes such as human serum and plasma. The new motion-driven protein isolation platform represents a new approach in bioanalytical chemistry based on active transport of proteins and offers considerable promise for diverse diagnostic applications

Dynamic Isolation and Unloading of Target Proteins by Aptamer-Modified Microtransporters

We describe here a new strategy for isolating target proteins from complex biological samples based on an aptamer-modified self-propelled microtube engine. For this purpose, a thiolated thrombin or a mixed thrombin–ATP aptamer (prehybridized with a thiolated short DNA) was coassembled with mercaptohexanol onto the gold surface of these microtube engines. The rapid movement of the aptamer-modified microtransporter resulted in highly selective and rapid capture of the target thrombin, with an effective discrimination against a large excess of nontarget proteins. Release of the captured thrombin can be triggered by the addition of ATP that can bind and displace the immobilized mixed thrombin–ATP aptamer in 20 min. The rapid loading and unloading abilities demonstrated by these selective microtransporters are illustrated in complex matrixes such as human serum and plasma. The new motion-driven protein isolation platform represents a new approach in bioanalytical chemistry based on active transport of proteins and offers considerable promise for diverse diagnostic applications

Artificial Enzyme-Powered Microfish for Water-Quality Testing

We present a novel micromotor-based strategy for water-quality testing based on changes in the propulsion behavior of artificial biocatalytic microswimmers in the presence of aquatic pollutants. The new micromotor toxicity testing concept mimics live-fish water testing and relies on the toxin-induced inhibition of the enzyme catalase, responsible for the biocatalytic bubble propulsion of tubular microengines. The locomotion and survival of the artificial microfish are thus impaired by exposure to a broad range of contaminants, that lead to distinct time-dependent irreversible losses in the catalase activity, and hence of the propulsion behavior. Such use of enzyme-powered biocompatible polymeric (PEDOT)/Au-catalase tubular microengine offers highly sensitive direct optical visualization of changes in the swimming behavior in the presence of common contaminants and hence to a direct real-time assessment of the water quality. Quantitative data on the adverse effects of the various toxins upon the swimming behavior of the enzyme-powered artificial swimmer are obtained by estimating common ecotoxicological parameters, including the EC_(50) (exposure concentration causing 50% attenuation of the microfish locomotion) and the swimmer survival time (lifetime expectancy). Such novel use of artificial microfish addresses major standardization and reproducibility problems as well as ethical concerns associated with live-fish toxicity assays and hence offers an attractive alternative to the common use of aquatic organisms for water-quality testing